Solid–liquid equilibrium of some polycyclic aromatic hydrocarbons in wash oil

2012 ◽  
Vol 319 ◽  
pp. 23-29 ◽  
Author(s):  
Yufeng Wei ◽  
Xiangyang Zhang ◽  
Jinyan Zhang ◽  
Leping Dang ◽  
Hongyuan Wei
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Liquid Equilibrium ◽  
Polycyclic Aromatic ◽  
Solid Liquid

scholarly journals The Effects of Three Traditional Smoking Methods on the Concentrations of Polycyclic Aromatic Hydrocarbons (PAHS) in Smoked Fishes

2021 ◽  
pp. 22-30
Author(s):  
Aderinola Oluwatoyin Joseph ◽  
A. A. Adu ◽  
O. O. Babalola ◽  
V. Kusemiju ◽  
G. O. Mekuleyi
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Low Income ◽  
Awareness Campaigns ◽  
Smoked Fish ◽  
Total Pahs ◽  
Scomber Scombrus ◽  
Fish Samples ◽  
Polycyclic Aromatic ◽  
Solid Liquid

The effects of three traditional smoking methods on the concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) in smoked fishes were studied to determine the concentration of PAHs in locally available and commonly consumed smoked fish species. Samples of two highly traded species of fish, Scomber scombrus and Horse markerel, among the low income people for immediate consumption were purchased from the market and processed using sawdust smoke, firewood smoke and charcoal smoke respectively. Some of the fresh fishes were also analyzed as control. The PAHs content were extracted with standard dichloromethane using solid-liquid extraction, and analyzed using Gas chromatography – Mass spectrophotometer (GC-MS) method. The results showed that fish samples processed with sawdust smoke recorded the highest concentrations of total PAHs, having 1.295 mg/kg in Horse markerel and 2.020 mg/kg in Scomber scombrus, followed by firewood smoked samples with total PAHs content of 0.910mg/kg in Horse markrel and 1.175 g/kg in Scomber scombrus while charcoal smoked samples recorded the least total PAHs levels of 0.590 mg/kg in Horse markerel and 0.960 mg/kg in Scomber scombrus. Benzo(a)pyrene concentrations which is usually used to estimate the carcinogenicity of other PAHs was below detection level in both species of fish. PAH4 was proposed by European food safety authority, recommendation level of 30 mg/kg was concluded by the EU regulation. Any PAHs have been associated with intense carcinogenicity in humans, and thus have implication for the quality and safety of these fish products. Therefore, it is imperative that regulatory bodies conduct awareness campaigns to educate the smoked fish processors, traders and consumers on the need to discourage the use of sawdust in smoking fish and adopt safer and improved methods of smoking fishes.

Sorption of Polycyclic Aromatic Hydrocarbons onto Natural Solids: Determination by Fluorescence Quenching Method

1991 ◽  
Vol 23 (1-3) ◽  
pp. 427-436 ◽  
Author(s):  
Y. Shimizu ◽  
H. M. Liljestrand
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Organic Carbon ◽  
Fluorescence Quenching ◽  
Aromatic Hydrocarbons ◽  
Organic Carbon Content ◽  
Polycyclic Aromatic ◽  
Fluorescence Quenching Method ◽  
Quenching Method ◽  
Solid Liquid ◽  
Solid Liquid Separation

A fluorescence quenching method was used to determine the sorption of polycyclic aromatic hydrocarbons (PAHs) onto natural solids in batch experiments. This method is based upon the observation that PAHs fluoresce in aqueous solution but not when associated with natural solids. It avoids problems of incomplete solid-liquid separation. As natural solids, eleven different USEPA soils and sediments were used. Anthracene and 2-aminoanthracene, which are respectively non-ionic and ionic PAHs, were chosen as sorbates. The fractional decrease in fluorescence intensity as a function of added natural solid concentration is referred to as Stem-Volmer plots. The plots were linear for all natural solids investigated. The conditional sorption coefficients (Ksc) at pH 6 through 8 and I=0.1 M were obtained as the slopes of the plots. While the Ksc values of anthracene were independent of pH, the values of 2-aminoanthracene decreased with increasing pH. The Ksc values of anthracene correlated well with the organic carbon content of natural solids. However, the values of 2-aminoanthracene did not depend on the content of organic carbon in natural solids. For 2-aminoanthracene, inorganic matrices of the natural solids may contribute to the sorption.

Comparing bulk extraction methods for chemically available polycyclic aromatic hydrocarbons with bioaccumulation in worms

2007 ◽  
Vol 4 (4) ◽  
pp. 271 ◽  
Author(s):  
Mickael Barthe ◽  
Émilien Pelletier
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Organic Contaminants ◽  
Extraction Procedure ◽  
Extraction Methods ◽  
Contaminated Sediments ◽  
Lumbriculus Variegatus ◽  
Exposure System ◽  
Polycyclic Aromatic ◽  
Solid Liquid

Environmental context. Determining the bioavailability of organic contaminants in sediments is a critical step in assessing the ecological risks of contamination in aquatic ecosystems. Standardised sediment bioaccumulation tests using benthic organisms are often performed to determine the relative bioavailability of sediment contamination. Unfortunately biological methods are time consuming, expensive and organisms are often difficult to maintain in good health in a laboratory exposure system. Contradictory results have been reported in the last decade and factors that affect the behaviour of extractants need to be examined for a large range of sediments. A study was conducted to determine the bioavailability of polycyclic aromatic hydrocarbons (PAHs) in sediment using worms and to compare the uptake by the biological samplers with mild solid/liquid extractions when exposed to unspiked low and highly contaminated marine and freshwater sediments. Abstract. The purpose of this study is to evaluate different techniques for assessing the availability of polycyclic aromatic hydrocarbons (PAHs) in contaminated sediments. This goal was achieved by comparing results from 28-day uptake experiments by Nereis virens and Lumbriculus variegatus with PAHs extracted by three non-exhaustive extraction methods using: n-Butanol (BuOH, 100%), an aqueous solution of hydroxypropyl-β-cyclodextrin (HPCD) and a surfactant solution of Brij700 (B700). Our results highlight the importance of considering both the PAH level in sediments and the molecular size of PAHs when attempting to predict their bioaccumulation in a biological sampler like worms using a solid/liquid extraction method. The surfactant B700 solution was quite successful to predict PAH bioaccumulation when exposed to unspiked highly contaminated sediments (25–5700 μg g–1). When low contaminated sediments (0.06–11 μg g–1) were used, HPCD and BuOH were better extractants for estimating bioaccumulation whereas B700 appeared to be too mild an extractant for most samples. Our results illustrate the interest and difficulties in finding an adequate chemical predictor for PAH bioavailabilty, particularly because PAH concentrations and sequestration processes play a determining role in the quality of results. Because B700 is not expansive and extraction solutions are easy to prepare, an extraction procedure involving this surfactant is proposed as a reliable predictor for aged highly contaminated sediments.

Fluorescence Line Narrowing Spectroscopy of Polycyclic Aromatic Hydrocarbons on Solid—Liquid Extraction Membranes

2003 ◽  
Vol 57 (6) ◽  
pp. 697-702 ◽  
Author(s):  
Adam J. Bystol ◽  
Andres D. Campiglia
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Water Sample ◽  
Aromatic Hydrocarbons ◽  
Liquid Extraction ◽  
Line Narrowing ◽  
Polycyclic Aromatic ◽  
Fluorescence Line ◽  
Fluorescence Line Narrowing ◽  
Solid Liquid Extraction ◽  
Solid Liquid

The potential of solid–liquid extraction fluorescence line narrowing spectroscopy is evaluated for screening polycyclic aromatic hydrocarbons in aqueous samples. Octadecyl silica membranes are used with the dual purpose of sample preconcentration and solid substrate for spectroscopic measurements. 4.2 K fluorescence line narrowed spectra are directly recorded from the membrane with the aid of a fiber-optic probe. The experimental procedure is free from organic solvents and takes less than 5 min per sample. With 10 mL of water sample, the limits of detection are at the parts-per-billion level. Qualitative analysis is based on wavelength time matrices, which provide a unique format for compound identification based on spectral and lifetime data. The selectivity of this approach is demonstrated with the unambiguous determination of naphthalene in a heavily contaminated water sample.

scholarly journals Nanopatterns of arylene–alkynylene squares on graphite: self-sorting and intercalation

2019 ◽  
Vol 15 ◽  
pp. 1848-1855 ◽  
Author(s):  
Tristan J Keller ◽  
Joshua Bahr ◽  
Kristin Gratzfeld ◽  
Nina Schönfelder ◽  
Marcin A Majewski ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Pyrolytic Graphite ◽  
Scanning Tunneling ◽  
Side Chains ◽  
Tunneling Microscopy ◽  
Polycyclic Aromatic ◽  
Solvent Molecules ◽  
Solid Liquid Interface ◽  
Solid Liquid

Supramolecular nanopatterns of arylene–alkynylene squares with side chains of different lengths are investigated by scanning tunneling microscopy at the solid/liquid interface of highly oriented pyrolytic graphite and 1,2,4-trichlorobenzene. Self-sorting leads to the intermolecular interdigitation of alkoxy side chains of identical length. Voids inside and between the squares are occupied by intercalated solvent molecules, which numbers depend on the sizes and shapes of the nanopores. In addition, planar and non-planar coronoid polycyclic aromatic hydrocarbons (i.e., butyloxy-substituted kekulene and octulene derivatives) are found to be able to intercalate into the intramolecular nanopores.

The Assessment of Contamination and Source of Polycyclic Aromatic Hydrocarbons from the Sediments of the Someş River

2019 ◽  
Vol 64 (1) ◽  
pp. 55-67
Author(s):  
Vlad Pӑnescu ◽  
◽  
Mihaela Cӑtӑlina Herghelegiu ◽  
Sorin Pop ◽  
Mircea Anton ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Polycyclic Aromatic
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